Manufacture of foam insulated refrigerator cabinets



Nov. 29, 1966 M. E. HENDRICKS MANUFACTURE OF FOAM INSULATED REFRIGERATOR CABINETS Filed June a, 1964 INVENTOR. MERvuQ Ev HEND'RKKS FWGJ \HS ATTORNEY United States Patent 3,288,896 MANUFACTURE OF FOAM INSULATED REFRIGERATOR CABINETS Mervin E. Hendricks, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed June 8, 1964, Ser. No. 373,198 Claims. (Cl. 264-45) The present invention relates to manufacture of foam insulated refrigerator cabinets and is more particularly concerned with the manufacture of cabinets in which an electrical lead or wire extends through and is at least partially embedded in the foam insulation.

Most refrigerator cabinets include a lamp for lighting the interior of the cabinet, that is, the storage space defined by the liner, when the door is opened and switch means mounted on the face of the cabinet and actuated by the opening and closing movement of the door for controlling the flow of current to the lamp. For appearance reasons, it is desirable that the wiring or leads connecting the switch to the lamp within the liner pass through the insulated space. In a foam insulated cabinet in which the foam tightly adheres to the surfaces of both the liner and shell and completely fills the space between these two members, it is necessary that the leads be preassembled on the liner before the foaming operation. It is also necessary that the ends of the leads to be attached to the switch means be readily accessible for connection to the switch means after the foaming operation.

In accordance with one well known method of manufacturing a foam insulated refrigerator cabinet including an inner liner, an outer shell spaced from the liner and foam resin insulation filling the space between the liner and shell, there is provided a liner having an outwardly extending strengthening flange surrounding the access opening thereto and a shell having an inwardly extending flange surrounding the access opening to the shell. The liner is placed in a foaming mold which includes an inner liner supporting member and an outer shell supporting member after which the shell is inserted into the foaming mold face down to a position in which the inner edge of the shell flange is spaced forwardly from the outer edge of the liner flange. The'foaming mold includes a portion which bridges the space between the two flanges during the foaming operation and after removal of the foamed cabinet from the mold this space is bridged by means of a breaker strip of insulating material.

The present invention has as its primary object the provision of an improved means of manufacturing such cabinets whereby the ends of the leads extending through the foam area will be readily available through the space between the shell and liner flanges.

Another object of the invention is to provide an improved method of positioning an electrical lead within the foamed space during the manufacture of a foamed cabinet so that the end of the lead will be available through the breaker strip area after the foaming operation has been completed.

Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In carrying out the objects of the present invention in the manufacture of a refrigerator cabinet including a shell member and a liner member spaced from one another with the space therebetween filled with foam insulation, the end portion of an electrical lead or wiring which are to be accessible through the area between the front edges of the two members are placed in an enclosure which is secured to the insulation side of one of the liners by resilient support means adapted to normally position the front end of the enclosure outwardly from the edge of the liner flange. The liner is then placed in a foaming mold. The enclosure is designed and mounted so that the outer wall thereof slants rearwardly towards the liner, on the resilient support means allowing the enclosure to be depressed against the liner surface to permit the introduction of the shell into the foaming mold, or more specifically to allow the shell flange to pass the enclosure. The enclosure is then returned to its normal position after the shell is in its final position in the mold.

For a better understanding of the invention reference may be had to the accompanying drawing in which:

FIGURE 1 is a sectional view of a portion of the cabinet manufactured in accordance with the present invention;

FIGURE 2 is a view illustrating one step in the manufacture of the cabinet in FIGURE 1;

FIGURE 3 is a view illustrating a subsequent step in the manufacture of the cabinet of FIGURE 1;

FIGURE 4 is a view taken generally along line 4-4 of FIGURE 3; and

FIGURE 5 is a sectional view of a second embodiment of the present invention.

With reference to FIGURE 1 of the accompanying drawing, there is illustrated, in section, a portion of one side wall of a refrigerator cabinet comprising a liner 1 defining a storage compartment and a shell 2 spaced from the liner, the space between the two being filled with a rigid resin foam insulating material 3 formed in place between the shell and liner members. The liner 1 includes an outwardly extending strengthening flange 4 extending entirely around the access opening to the storage compartment while the outer shell member 2 comprises an inwardly extending strengthening flange 5 extending entirely around the forward edge thereof. The flange 5 is spaced forwardly from the flange 4 and the space between these two flanges is bridged by means of a breaker strip 6.

Mounted on the breaker strip 6 is a light switch 7 connected by a lead or leads 8 to an electric lamp (not shown) mounted within the rear portion of the storage compartment defined by the liner 1. The switch includes a button 9 adapted to be engaged by the door (not shown) for closing the access opening to the cabinet whenever the door is closed to interrupt the flow of current to the lamp.

In the manufacture of a foam insulated cabinet of this type, the liner and shell are assembled in a suitable foaming mold or fixture designed to support the walls thereof and to maintain them in their final spaced relationship. A foam forming resin such as a foamable polyurethane resin, is then introduced into the space between the two members or it is allowed to foam and cure to entirely fill the space.

The essential elements of a mold required for the practice of the present invention are illustrated in FIGURES 2 and 3 of the drawing. The foaming mold comprises an outer box-like wall structure 11 for supporting the entire side and end walls of the shell member during the foaming operation and a liner supporting member 12 centrally positioned within the mold and having the same shape as the interior of the liner 2 so that it supports all of the liner walls against the pressures generated by the foaming resin. A bottom wall 14 of the mold supports the forward edge or flange portion 5 of the shell and a shoulder 15 provided on the member 12 supports the flange 4 of the liner when it is positioned face down in the mold.

In the use of a mold of this type for manufacturing an insulated cabinet, the liner 1 is placed over the member 12 with the flange 4 resting on the shoulder 15. The shell 2 is then inserted into the mold and passes telescopically over the liner 1 until the flange 5 rests on the bottom Wall 14 of the mold. With the liner and shell member-s properly positioned within the mold, a foamable resin is introduced into the space between the two members and allowed to foam and cure to provide the insulation 3.

Due to the excellent heat insulating properties of resin foam insulation, the walls of the cabinet can be relatively thin or in other words the space between the walls of the liner 1 and the walls of the shell 2 can be greatly reduced as compared with cabinets containing glass fiber insulation. As a result there is very little clearance between the outer edge 16 of the flange 4 and the inner edge 17 of the flange 5 as the shell 2 is slid into the mold over the liner 1. As a result any leads which are embedded within the insulation 3 and which must be accessible through the gap between the two flanges, for connection to electrical means such as the switch 7 after foaming of the cabinet have previously been taped to liner 1 rearwardly from the flange 4 prior to the foaming operation. This required the operator to remove not only portions of the foam between the two flanges 4 and 5 but also to dig behind the flange 4 in order to gain access to the leads.

In accordance with the present invention, means are provided whereby the desired portion of the electrical lead is readily accessible in an area which is not shielded by the liner flange 4 after the foaming operation. To this end the portions of the leads 8 which are to be connected to the switch 7 are enclosed in an enclosure 18 and this enclosure is then secured by means of resilient members 19 to the foamed side 20 of the liner 1 using any suitable means such as an adhesive to secure these components together. The enclosure 18 is mounted on the liner 1 with its forward end 22 adjacent to and rearwardly from the flange 4 and the resilient member or members 19 are of a thickness such that the end 22 is positioned outwardly from the edge 16 of the flange 4, in a position which is directly behind the shell flange 5 after the shell is placed in the mold. With the enclosure 18 thus mounted on the liner 1 the liner is positioned on the inner mold support member 12 after which the shell 2 is inserted into the mold and telescopically moved down over the liner 1.

In order to permit the flange 5 on the shell 2 to pass the enclosure 18 without dislodging it from its normal position relative to the liner 1, the back end of the enclosure is provided with a sloping wall portion 24 so that initial engagement of the inner edge 17 of the flange 5 with this sloping wall portion 24 compresses the resilient support means 19 and causes the enclosure 18 to move towards the liner 1 so that the flange 5 can pass freely by the enclosure 18 toits normal position within the mold. As soon as the flange 5 has cleared the forward end 22 of the enclosure 18, the enclosure is returned to its normal position by the resilient means 19. The subsequent formation of the foam insulating material within the space between the liner and shell embeds the enclosure 18 within the foam insulation 3 with the enclosure in its normal position which is now rearwardly from flange 5 and outwardly from the flange 4.

In order to prevent foam from entering the forward end of the enclosure, this end 22 may be closed by means of a suitable paper tape or the like which can be easily punctured, or if desired, it may be left open and a tape 27 applied across the front of the enclosure so that it generally covers the end 22 and bridges the space between the outer wallof the enclosure and the flange 4 as illustrated in FIGURES 2 and 3 of the drawing. Also, if desired, a suitable plunger 25 may be incorporated in the mold. The plunger 25 is normally retracted but is adapted to be moved forwardly into the space between the liner 1 and the shell 2 to form a cavity in the foam during the foaming operation so as to facilitate access to the front of the enclosure 18 after removal of the cabinet from the mold.

Following removal of the foamed cabinet from the mold, the operator need only remove the portion of the tape 27 in front of the finclosure 18 in order to gain access to the end portions of the leads or wiring 8 contained therein. These end portions are then brought forwardly to a position in which they can be connected to the switch means 7 during assembly of the switch means and breaker strip 6 on the face of the cabinet.

In the embodiment of the invention illustrated in FIG- URE 5 of the drawing, the enclosure 18, instead of having a sloping rear wall portion 24, is secured, to the cabi net so that its outer wall 28, or in other words the wall engaged by the flange 5 during assembly of the shell and liner in the foaming mold slopes relative to the liner or in other words, is closer to the liner at the rear end thereof than at the forward end. This is accomplished by using only a single resilient means 19 for supporting the front end 22 of the enclosure in its desired spaced position relative to the flange 4 and fastening the rear end 30 of the enclosure in direct engagement with the foamed side of the liner 1.

The resilient means 19 may be of any suitable resilient material such as a flexible polyurethane foam or a foamed rubber, adapted to permit the enclosure 18 to move towards the liner during insertion of the shell 2 into the mold and to return the enclosure 18 to a position in which the forward end 22 thereof is outwardly from the flange 4 after the liner and shell are positioned within the foam mold.

While there has been shown and described particular embodiments of the present invention, it will be understood that the invention is not limited thereto and it is intended by the appended claims to cover all modifications that fall within the spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In the method of manufacturing a foam insulated cabinet including the method steps of positioning said liner in a foaming mold, positioning a cabinet shell in said mold over said liner, and foaming resin in the space between said liner and shell; the improvement which comprises mounting an electrical lead on said liner, enclosing portion of said lead in an enclosure and securing said enclosure to and in normally spaced relationship with the foam side of said liner by resilient means adapted to permit said enclosure to move from its normal position towards said liner upon contact of a portion of said shell therewith during positioning of said shell in said mold and to return said enclosure to its normal position after said shell portion moves past said enclosure.

2. In the method of manufacturing a foam insulated cabinet having an electrical lead embedded in the foam insulation which method comprises mounting said lead on a cabinet liner, positioning said liner in a foaming mold, positioning a cabinet shell in said mold over said liner, and introducing a foam forming resin in the space between said shell and liner; the improvement which comprises enclosing a portion of said lead in an enclosure and securing said enclosure to and in normally spaced relationship with the foam side of said liner by resilient means adapted to permit said enclosure to move from its normal position towards said liner upon contact of a portion of said shell therewith during positioning of said shell in said mold and to return said enclosure to its normal position after said shell portion moves past said enclosure.

3. In the method of manufacturing a foam insulated cabinet including a liner having an outwardly extending flange surrounding the access opening thereto and a shell having an inwardly extending flange surrounding the access opening thereto by employing a foaming mold including fixed inner and outer supports for supporting and positioning said liner and shell during the foaming operation, positioning said liner on said inner support, sliding said shell into said mold a distance such that said shell flange passes said liner flange to provide a gap between said flanges, and thereafter introducing a foamable resin into the space between said shell and liner, the improvement which comprises:

preassembling with said liner, an electrical lead adapted to have a portion accessible through said gap, enclosing said portion in an enclosure, and

supporting said enclosure on said liner by means of a resilient support adapted to normally position the forward end of said enclosure adjacent to and outwardly from said liner flange,

compression of said resilient support by contact of said shell flange permitting said shell to pass said enclosure as said shell is inserted into said mold.

4. In the method of manufacturing a foam insulated cabinet including a liner having an outwardly extending flange surrounding the access opening thereto and a shell having an inwardly extending flange surrounding the access opening thereto by employing a foaming mold including fixed inner and outer supports for supporting and positioning said liner and shell during the foaming operation, positioning said liner on said inner support, slding said shell into said mold a distance such that said shell flange passes said liner flange to provide a gap between said flanges, and thereafter introducing a foarnable resin into the space between said shell and liner, the improvement which comprises:

preassembling with said liner, prior to positioning of said shell in said mold, an electrical lead adapted to have an end portion accessible through said gap, enclosing said end portion in an enclosure, and

supporting said enclosure on said liner by means of a resilient support adapted to normally position one end of said enclosure adjacent to and outwardly from said liner flange,

said resilient support being adapted to be compressed by contact of said shell flange with said enclosure as said shell is slid into said mold and to return said enclosure to its normal position prior to introduction of said foamable resin.

5. The method of making a plastic foam insulated cabinet comprising a liner including walls defining a storage compartment and having an access opening at the front thereof and an outwardly extending flange surrounding said opening, an outer shell spaced from said liner and including an inwardly extending flange at the front thereof having an inner edge spaced forwardly from the outer edge of said outwardly extending flange, foam insulation formed in place in the space between said liner and shell, electrical means mounted adjacent said liner access opening and an electric lead having a portion connected to said electrical means and extending from said electrical means through said foam insulation and through said liner at a point spaced from said outwardly extending flange, which method comprises;

placing said liner face down in a foaming mold including a liner supporting member and outer walls defining a shell supporting member and a bottom portion for supporting the flanges on said shell and said liner, sliding said shell into said mold over said liner, and introducing a foam forming plastic material into space between said liner and shell, the improvement comprising; mounting said lead on said liner and enclosing said portion thereof in an enclosure prior to the insertion of said shell into said mold, securing said enclosure to the outer surface of said liner with one end thereof adjacent to and rearwardly from said outwardly extending flange by resilient support means adapted to normally position said front end of said enclosure outwardly from said edge of said outwardly extending flange and the rear end slanted toward said liner, whereby when said shell is inserted into said mold, said enclosure is adapted to be depressed by said shell flange to permit said shell flange to pass said enclosure and to be returned to its normal position prior to the introduction of said foam forming plastic whereby said lead portion is accessible through the front end of said enclosure.

References Cited by the Examiner UNITED STATES PATENTS 3,091,946 6/1963 Kesling 264-45 X 3,150,796 9/1964 Hocking et a1 26445 X 3,152,199 10/1964 Roberts 264-45 3,177,271 4/1965 Slayrnan 264-45 ROBERT F. WHITE, Primary Examiner.

P. E. ANDERSON, Assistant Examiner. 

1. IN THE METHOD OF MANUFACTURING A FOAM INSULATED CABINET INCLUDING THE METHOD STEPS OF POSITIONING SAID LINER IN A FOAMING MOLD, POSITIONING A CABINET SHELL IN SAID MOLD OVER SAID LINER, AND FOAMING RESIN IN THE SPACE BETWEEN SAID LINER AND SHELL; THE IMPROVEMENT WHICH COMPRISES MOUNTING AN ELECTRICAL LEAD ON SAID LINER, ENCLOSING PORTION OF SAID LEAD IN AN ENCLOSURE AND SECURING SAID ENCLOSURE TO AND IN NORMALLY SPACED RELATIONSHIP WITH THE FOAM SIDE OF SAID LINER BY RESILIENT MEANS ADAPTED TO PERMIT SAID ENCLOSURE TO MOVE FROM ITS NORMAL POSITION TOWARDS SAID LINER UPON CONTACT OF A PORTION OF SAID SHELL THEREWITH DURING POSITIONING OF SAID SHELL IN SAID MOLD AND TO RETURN SAID ENCLOSURE TO ITS NORMAL POSITION AFTER SAID SHELL POSITION MOVES SAID ENCLOSURE. 